This invention generally relates to improvements in electrical switches, and in particular relates to switches which have a minimal number of parts, are small in size, can be manufactured at a reduced cost, and yet remain rugged, reliable and contaminant resistant. The invention further relates to switches of the type described which are capable of providing the operator with tactile feedback, i.e. sensory information that the switch has been actuated from an open circuit position to a closed circuit position, and vice versa.
There have been many attempts to develop inexpensive, yet reliable electrical switches which have these capabilities, some of which have met with substantial success. Nonetheless, because of increasing pressures to reduce costs, the need still exists for an improved, low cost electrical switch. The switch disclosed herein was developed to satisfy that need.
In summary, the improved electrical switch herein disclosed comprises a two-piece housing having a base and an escutcheon. The escutcheon preferably includes an integrally formed face plate comprising a flexible, resilient, insulative membrane. A first electrical contact is secured to the base in alignment with the face plate, and a second electrical contact is also secured to the base, preferably offset from the first contact. Electrically conductive means, such as a snap action dome, has a center portion normally disposed above the first contact, and a peripheral portion electrically connected to said second contact. The face plate is adapted to move a sufficient distance in response to applied pressure to force the center portion of the dome into contact with the first electrical contact, thereby providing a temporary electrical connection between the first and second contacts. The face plate is further adapted to return to its original position upon release of the pressure so applied, thereby breaking said temporary electrical connection.